I am learning Spring using the Spring In Action (Edition 3) book. I have come across an example in the book thats not working for me. Following is the detail:
I am trying to use Spring AOP to introduce new functionality in a bean:
Here is the class structure:
- Instrumentalist implements Performer
- GraciousContestant implements Contestant
Performer interface
public interface Performer {
void perform();
}
Class Instrumentalist
package chapter4;
public class Instrmentalist implements Performer {
public void perform() {
System.out.println("Sining hey hey, hey");
}
}
Contestant Interface
package chapter4;
public interface Contestant {
void receiveAward();
}
GraciousContestant Class
package chapter4;
public class GraciousContestant implements Contestant {
public void receiveAward() {
System.out.println("Won a car worth 4K!");
}
}
My spring configuaration file called “spring-idol2.xml” is as below:
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.1.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsd">
<bean id="ken" class="chapter4.Instrmentalist" />
<bean id="contestantDelegate" class="chapter4.GraciousContestant" />
<aop:config>
<aop:aspect>
<aop:declare-parents
types-matching="chapter4.Performer+"
implement-interface="chapter4.Contestant"
delegate-ref="contestantDelegate"/>
</aop:aspect>
<aop:aspect ref="ken">
<aop:pointcut id="performance"
expression="execution(* chapter4.Performer.perform(..))" />
<aop:after pointcut-ref="performance" method="receiveAward"/>
</aop:aspect>
</aop:config>
</beans>
My Main method looks like this:
package chapter4;
import org.springframework.context.support.AbstractApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class TestMain {
public static void main(String[] args) {
AbstractApplicationContext context =
new ClassPathXmlApplicationContext("/chapter4/spring-idol2.xml");
Performer p1 = (Performer) context.getBean("ken");
p1.perform();
}
}
What is supposed to be printed out is as follows:
Sining hey hey, hey
Won a car worth 4K!
However I get the following error:
Exception in thread "main" org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'ken' defined in class path resource [chapter4/spring-idol2.xml]: BeanPostProcessor before instantiation of bean failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.aop.aspectj.DeclareParentsAdvisor#0': Cannot resolve reference to bean 'contestantDelegate' while setting constructor argument; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'contestantDelegate' defined in class path resource [chapter4/spring-idol2.xml]: BeanPostProcessor before instantiation of bean failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.aop.aspectj.AspectJPointcutAdvisor#0': Cannot create inner bean '(inner bean)' of type [org.springframework.aop.aspectj.AspectJAfterAdvice] while setting constructor argument; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name '(inner bean)': Cannot create inner bean '(inner bean)' of type [org.springframework.aop.config.MethodLocatingFactoryBean] while setting constructor argument; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name '(inner bean)': Initialization of bean failed; nested exception is java.lang.IllegalArgumentException: Unable to locate method [receiveAward] on bean [ken]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:452)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:295)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:292)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:580)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:900)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:455)
at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:139)
at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:83)
at chapter4.TestMain.main(TestMain.java:13)
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.aop.aspectj.DeclareParentsAdvisor#0': Cannot resolve reference to bean 'contestantDelegate' while setting constructor argument; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'contestantDelegate' defined in class path resource [chapter4/spring-idol2.xml]: BeanPostProcessor before instantiation of bean failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.aop.aspectj.AspectJPointcutAdvisor#0': Cannot create inner bean '(inner bean)' of type [org.springframework.aop.aspectj.AspectJAfterAdvice] while setting constructor argument; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name '(inner bean)': Cannot create inner bean '(inner bean)' of type [org.springframework.aop.config.MethodLocatingFactoryBean] while setting constructor argument; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name '(inner bean)': Initialization of bean failed; nested exception is java.lang.IllegalArgumentException: Unable to locate method [receiveAward] on bean [ken]
at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:328)
at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:106)
at org.springframework.beans.factory.support.ConstructorResolver.resolveConstructorArguments(ConstructorResolver.java:616)
at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:148)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1003)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:907)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:485)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:295)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:292)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:198)
at org.springframework.aop.framework.autoproxy.BeanFactoryAdvisorRetrievalHelper.findAdvisorBeans(BeanFactoryAdvisorRetrievalHelper.java:86)
at org.springframework.aop.framework.autoproxy.AbstractAdvisorAutoProxyCreator.findCandidateAdvisors(AbstractAdvisorAutoProxyCreator.java:100)
at org.springframework.aop.aspectj.autoproxy.AspectJAwareAdvisorAutoProxyCreator.shouldSkip(AspectJAwareAdvisorAutoProxyCreator.java:107)
at org.springframework.aop.framework.autoproxy.AbstractAutoProxyCreator.postProcessBeforeInstantiation(AbstractAutoProxyCreator.java:278)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsBeforeInstantiation(AbstractAutowireCapableBeanFactory.java:848)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.resolveBeforeInstantiation(AbstractAutowireCapableBeanFactory.java:820)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:446)
... 10 more
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'contestantDelegate' defined in class path resource [chapter4/spring-idol2.xml]: BeanPostProcessor before instantiation of bean failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.aop.aspectj.AspectJPointcutAdvisor#0': Cannot create inner bean '(inner bean)' of type [org.springframework.aop.aspectj.AspectJAfterAdvice] while setting constructor argument; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name '(inner bean)': Cannot create inner bean '(inner bean)' of type [org.springframework.aop.config.MethodLocatingFactoryBean] while setting constructor argument; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name '(inner bean)': Initialization of bean failed; nested exception is java.lang.IllegalArgumentException: Unable to locate method [receiveAward] on bean [ken]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:452)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:295)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:292)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194)
at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:322)
... 28 more
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.aop.aspectj.AspectJPointcutAdvisor#0': Cannot create inner bean '(inner bean)' of type [org.springframework.aop.aspectj.AspectJAfterAdvice] while setting constructor argument; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name '(inner bean)': Cannot create inner bean '(inner bean)' of type [org.springframework.aop.config.MethodLocatingFactoryBean] while setting constructor argument; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name '(inner bean)': Initialization of bean failed; nested exception is java.lang.IllegalArgumentException: Unable to locate method [receiveAward] on bean [ken]
at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveInnerBean(BeanDefinitionValueResolver.java:281)
at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:125)
at org.springframework.beans.factory.support.ConstructorResolver.resolveConstructorArguments(ConstructorResolver.java:630)
at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:148)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1003)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:907)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:485)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:295)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:292)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:198)
at org.springframework.aop.framework.autoproxy.BeanFactoryAdvisorRetrievalHelper.findAdvisorBeans(BeanFactoryAdvisorRetrievalHelper.java:86)
at org.springframework.aop.framework.autoproxy.AbstractAdvisorAutoProxyCreator.findCandidateAdvisors(AbstractAdvisorAutoProxyCreator.java:100)
at org.springframework.aop.aspectj.autoproxy.AspectJAwareAdvisorAutoProxyCreator.shouldSkip(AspectJAwareAdvisorAutoProxyCreator.java:107)
at org.springframework.aop.framework.autoproxy.AbstractAutoProxyCreator.postProcessBeforeInstantiation(AbstractAutoProxyCreator.java:278)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsBeforeInstantiation(AbstractAutowireCapableBeanFactory.java:848)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.resolveBeforeInstantiation(AbstractAutowireCapableBeanFactory.java:820)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:446)
... 33 more
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name '(inner bean)': Cannot create inner bean '(inner bean)' of type [org.springframework.aop.config.MethodLocatingFactoryBean] while setting constructor argument; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name '(inner bean)': Initialization of bean failed; nested exception is java.lang.IllegalArgumentException: Unable to locate method [receiveAward] on bean [ken]
at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveInnerBean(BeanDefinitionValueResolver.java:281)
at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:125)
at org.springframework.beans.factory.support.ConstructorResolver.resolveConstructorArguments(ConstructorResolver.java:616)
at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:148)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1003)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:907)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:485)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveInnerBean(BeanDefinitionValueResolver.java:270)
... 51 more
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name '(inner bean)': Initialization of bean failed; nested exception is java.lang.IllegalArgumentException: Unable to locate method [receiveAward] on bean [ken]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:527)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveInnerBean(BeanDefinitionValueResolver.java:270)
... 59 more
Caused by: java.lang.IllegalArgumentException: Unable to locate method [receiveAward] on bean [ken]
at org.springframework.aop.config.MethodLocatingFactoryBean.setBeanFactory(MethodLocatingFactoryBean.java:75)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeAwareMethods(AbstractAutowireCapableBeanFactory.java:1440)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1408)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:519)
... 61 more
Could someone kindly explain to me why it says “Unable to locate method [receiveAward] on bean [ken]” even though I have declared a parent? Is the syntax wrong?
Thank you very much,
regards,
Khush.
Note that
<aop:config>sees beans before aspects are applied, therefore I guess that you can’t use methods introduced by<aop:declare-parents>in other aspect declarations.If you want to check whether
<aop:declare-parents>worked, you can do something like this: